Nancy Guthrie case: Former FBI agent explains why probe is going in circles; ‘they're retracing…'

A former FBI agent explains why the search for Nancy Guthrie is going deeper after weeks with no leads.

More than six weeks after Nancy Guthrie disappeared from her Tucson home, a former FBI agent is shedding light on why the investigation may appear to be going in circles.

Ex-Investigator explains why investigators are retracing steps in Nancy Guthrie disappearance (via REUTERS)

84-year-old Nancy, mother of Savannah Guthrie was reported missing on February 1 and despite 45 days of searching, there have been no major leads or suspects and authorities have not confirmed where she might be.

Why the investigation is going deeper

In a recent interview with Brian Entin of Brian Entin Investigates, former FBI agent Steve Moore explained that investigators are now likely going back over earlier steps and checking things they may not have focused on before.

Some neighbors questioned why certain leads, like contractors working nearby, were only being looked into now. Moore said this is actually a normal part of an investigation.

"Obviously, it means they're retracing steps. And I've used this analogy with you before. Say, you can't find your car keys and you go walk through the house or the apartment you look for where you usually leave them," Moore explained.

"They're not there. Then you have to go back and you have to go back and you have to retrace and you have to say, 'Hey, what pants was I wearing?" or 'Where's my purse?' or whatever, like that, and you go to the second level."

"When you get down to the third or fourth level these things are things you don't usually check, but you may start pulling cushions off beds or off couches things like that. You'll go in deeper and deeper and deeper."

What ‘pulling up cushions’ means

Moore said investigators usually start with the most obvious places and leads first. Only when those do not work do they begin checking less obvious possibilities.

"So people ask why didn't the FBI do this all already? Because the normal search yields your keys in about 20 seconds," he said.

"The secondary search yields them in about 2-5 minutes. And if you start with undoing the couches, the couch cushions in your living room you'll never get to the bedroom where the keys are."

Referring to the case, he added that investigators are now at that deeper stage.

"So they now are obviously to the point where they are pulling up cushions in the couch and I think that would explain they are not actually at day two, though I understand completely why it seems that way."

"They are where they would have been if all else, all normal searches, didn't work."

The case remains confusing even after more than 45 days. Police have not identified any suspects. The investigation is ongoing as authorities continue to search for answers.

Meanwhile, Savannah Guthrie and her family have offered a $1 million reward for anyone who provides information that could help “bring her home.” Officials say the investigation remains active as the search for Nancy continues.